1. Field of the Invention
The present invention relates generally to the construction and use of percutaneous access devices in performing laparoscopic and related endoscopic surgical procedures. More particularly, the present invention relates to a device and method for in situ cleaning of laparoscopes and other viewing scopes used in such surgical procedures.
Laparoscopic and other endoscopic surgical procedures rely on percutaneous introduction of a viewing scope into an internal region within the patient where the surgical procedure is to be performed. In the case of laparoscopic procedures, the viewing scope is commonly referred to as an endoscope or a laparoscope, and the laparoscope is commonly introduced through an access tube, such as a trocar, which passes into the patient's abdomen. The abdomen will have been insufflated to provide a working region. Using a laparoscope introduced through a trocar, the surgeon can view the region to be treated on a video monitor and can perform a variety of surgical procedures using specialized surgical instruments which are introduced percutaneously either directly or through trocars or other access tubes. Exemplary procedures which may be performed laparoscopically include cholecystectomy, hysterectomy, gastrostomy, appendectomy, bowel resection, herniorrhaphy, and the like. Analogous surgical procedures may be performed elsewhere in the body using other conventional viewing scopes, such as endoscopes, arthroscopes, thoracoscopes, bronchioscopes, hysteroscopes, choledochoscopes, cystoscopes, resectoscopes, and the like.
In all such procedures which employ internally-introduced viewing scopes, problems can arise with fogging and fouling of the distal lens of the scope which provides the optical access. The most common approach for dealing with such obscuring of the distal lens has been to remove the viewing scope and to manually clean it. For example, commercial products are available comprising a sponge or fabric pad and a bottle of cleaning solution. The surgeon can saturate the sponge with the cleaning solution, and clean the distal lens by removing the viewing scope from the patient, wiping the distal lens against the sponge, and returning the viewing scope to the patient. While effective, the need to withdraw the viewing scope from the patient, clean it, reinsert it, and relocate the target, is highly inefficient and inconvenient.
It has also been proposed to incorporate a spray wash nozzle on the viewing scope itself in order to permit cleaning of a distal lens without removing the scope from the patient. While addressing the needs of efficiency, the requirement of incorporating a washing system in the viewing scope itself does not permit cleaning of existing viewing scopes which are already in use. Such viewing scopes can be relatively expensive, limiting the ability to replace such scopes with models incorporating a wash system. Moreover, incorporation of at least one additional lumen and associated hardware for the wash system further complicates construction of the viewing scope, making it more expensive and requiring a larger diameter. Additionally, washing of a distal lens while the viewing scope is in place will not always be effective in cleaning the lens. Many times, it will still be necessary to withdraw the viewing scope to actually wipe the lens clean.
For these reasons, it would be desirable to provide alternative devices and methods for cleaning surgical viewing scopes in situ, i.e., without the need to remove the viewing scope from the patient. Such devices and methods should not require the modification of the viewing scope in any manner, and should preferably require minimum or no modification of other instruments used in performing the surgical procedure, e.g., trocars used for introducing the viewing scope. Such devices and methods should be very effective in removing contaminating debris and fogging of the distal lens of the viewing scope, should be convenient to use, and should be low-cost to implement. Some or all of these objectives will be met by the various embodiments of the present invention described hereinafter.
2. Description of the Background Art
U.S. Pat. No. 4,656,999, describes a contact endoscope having a slidable blade for severing tissue at its distal end. EP 497 347 describes a laparoscope having a lens washing nozzle at its distal end. Scope washing systems are also described in U.S. Pat. Nos. 5,207,213; 4,841,952; 4,760,838; and 4,646,722. U.S. Pat. No. 4,684,874, describes a dissolvable membrane which covers an endoscope lens to protect the lens while being inserted into a patient. U.S. Pat. No. 4,682,585, discloses an endoscope having annular depressions intended to remove contaminants while passing through a trocar. U.S. Pat. No. 4,919,113, describes a spray cleaner for an endoscope. U.S. Pat. No. 4,177,814, describes a self-sealing cannula having an elastomeric valve at its proximal end. Dexide, Fort Worth, Tex., sells a fog reduction/elimination device (FRED) which comprises a sponge and a bottle of cleaning solution, where a scope is removed from the patient to permit cleaning by the sponge. U.S. Pat. Nos. 5,127,909; 5,053,016; and 4,943,280, describe trocar assemblies having flapper valves at their proximal ends for sealing against insufflation pressure. A radially expanding dilator which can incorporate the cleaning assembly of the present invention is described in U.S. Pat. No. 5,183,464.